Blowing Smoke

Recent editorials by timber industry spokespersons are a wildly misleading attempt to promote increased logging of western U.S. forests under the guise of reducing wildland fires and mitigating climate change. The timber industry fails to mention, however, that logging is one of the major contributors to greenhouse gas emissions (Schlesinger, “Biogeochemistry: an analysis of global change”, Academic Press, 1997). A recent scientific study found that completely protecting our national forests from all commercial logging would significantly increase carbon sequestration and reduce greenhouse gases (forests “breath in” CO2 and incorporate the carbon into new growth), while increasing logging on our public lands would have the opposite effect (Depro et al. 2008, Forest Ecology and Management, Vol. 255).

The logging industry also makes numerous scientifically-inaccurate assumptions about fire. For example, the industry would have us believe that little or no natural growth of forest will occur after wildland fire. In fact, some of the most vigorous and productive forest growth occurs after burns, including in high severity fire areas in which most or all of the trees were killed (Shatford and others 2007, Journal of Forestry, May 2007).

Fire converts woody material on the forest floor from relatively unusable forms into highly useable nutrients, which aids forest productivity and carbon sequestration. The rapid forest growth following wildland fire sequesters huge amounts of the greenhouse gas carbon dioxide (CO2). Whatever carbon emissions occur from combustion during wildland fire and subsequent decay of fire-killed trees is more than balanced by forest growth across the landscape over time. To put the issue in perspective, current emissions from forest fires are only a tiny fraction of those from fossil fuel consumption, and carbon sequestration from forest growth far outweighs carbon emissions from fire.

The timber industry also incorrectly claims that, when fire-killed trees fall and decay, essentially all of the carbon in the wood is emitted into the atmosphere. In reality, much of the carbon ends up in the soil (Schlesinger 1997), and is assimilated into the growing forest. Moreover, the timber industry falsely claims that logging facilitates permanent carbon sequestration ostensibly by converting living forests into lumber. In fact, most of the carbon from a felled tree is either burned as slash or as “hog fuel” from mill residue; only about 15% becomes some type of durable wood product (A. Ingerson, 2007, The Wilderness Society, Washington, D.C.). The half-life of these “durable” wood products is less than 40 years (Smith et al. 2005, U.S. Forest Service Northeast Gen. Tech. Rpt. 34).

Logging industry spokespersons also greatly exaggerate the percentage of trees killed by fire. The Forest Service’s own data shows that, contrary to popular myth, low and moderate severity effects (where most overstory trees survive) dominate current wildland fires (Forest Service data in Rhodes and Baker 2008, Open Forest Science Journal, Vol. 1). Modern fires are a mix of low, moderate, and high severity effects, just as they were historically, prior to fire suppression programs. The main difference between then and now is that the total area of forest annually affected by fire currently is only about one-tenth of what it was prior to 1850, due to fire suppression (Stephens and others 2007, Forest Ecology and Management, Vol. 251).

Native species have evolved with fire over millennia in western forests, and many depend upon post-fire habitat. Interestingly, some of the highest levels of native biodiversity among animals and higher plants are found in unlogged forested areas that have burned at high severity (Noss and others 2006, Frontiers in Ecology and Environment, Vol. 4).

It’s important for people to know the facts about fire, ecosystems, and climate. Unfortunately, the timber industry is less interested in the truth than it is in misleading people to serve its own economic goals.

Dr. CHAD HANSONhas a Ph.D. in Ecology from the University of California at Davis, where he conducts post-doctoral research on fire ecology. He has authored or co-authored numerous scientific studies on the subject of forest and fire ecology. He is also the director of the John Muir Project, based in Cedar Ridge, CA. He can be reached at: cthanson@ucdavis.edu